How to monitor pollution with your smartphone

Sure, you think your phone is smart because it's an all-in-one device -- GPS, web browser, phone, camera, etc. But researchers are showing how smartphones can be used for more than just posting your Instagram photos to Facebook.

Computer scientists at the University of California, San Diego have developed small portable air pollution sensors. Known as CitiSense, the sensor system measures air quality levels in real time and delivers data to your smartphone or computer. It can detect ozone, nitrogen dioxide, carbon monoxide, and common air pollutants from vehicles and show how the pollution compares to national air quality standards in the United States.

The researchers say the portable sensors could be used by people with conditions, like chronic asthma, that make it especially important to avoid air pollution. It could also be used by commuters who bike or walk to work to find the least polluted route.

For now the sensors seem a bit clunky to carry around (here's an example) but the researchers say that one day sensors could actually be built into smartphones. And that could give cities a clearer look at when and where air pollution is the worst, far more than what's currently available from the United States' Environmental Protection Agency. As the university points out, San Diego County has 3.1 million people over 4,000 square miles, but only 10 air pollution monitoring stations.

“We want to get more data and better data, which we can provide to the public,” said William Griswold, a computer science professor at UC San Diego and the lead investigator on the project, in a statement. “We are making the invisible visible.”